For a long time already motor vehicles with automated multistep change-speed transmissions have been known, such as converter automatic transmissions, automated change-speed transmissions and automated dual-clutch transmissions, in which the shift operations can be carried out optionally in an automatic mode with operating-parameter-dependent, program-controlled shift initiation and in a manual mode with manual shift initiation. In the automatic mode the shifts are initiated automatically by virtue of stored shift characteristics or shift performance graphs as a function of operating parameters detected by sensors, such as driving speed, accelerator pedal position, engine load and engine speed. In contrast, in the manual mode shifts are initiated by the driver himself, by actuating corresponding shift actuation elements such as a selector lever in a shift console (within a manual shift gate) and shift buttons or shift keys arranged on the steering wheel.
In the automatic mode the shifting speeds, gear intervals and shift sequence of shift operations are determined essentially by the driving strategy of the shift program concerned, i.e. by an imposed operating property of the motor vehicle or its drivetrain followed by the shift program, such as the lowest possible fuel consumption, the greatest possible driving comfort or the maximum possible driving dynamics. To enable the driver to choose between a number of driving strategies, there is often a choice between at least two shift programs. These are for example an eco-shift program with relatively low shift speeds in order to achieve low fuel consumption, and a sporty shift program with relatively high shift speeds to achieve high acceleration ability, between which the driver can choose by operating a selector switch arranged on the shift console or on the steering wheel. It has even been proposed that the selection and actuation of the shift program should take place automatically in each case, by a driver-type determination based on sensor detection of the driver's driving behavior and/or the movement dynamics of the motor vehicle.
However, since for most drivers the possibility of choosing between two or three shift programs does not enable a satisfactory adaptation of the shifting behavior to their personal driving habits, several proposals have already been made for adapting the shifting behavior of an automated multistep change-speed transmission to suit individual drivers.
For example, in DE 694 03 419 T2 (EP 0 645 559 B1) a control device for an automatic transmission is described, with which in the manual mode a learning mode can be activated, in which, whenever a shift is initiated manually, operating parameters are detected and evaluated for the determination of driver-specific shift programs, i.e. shift characteristic or performance graphs that correspond to individual drivers. The operating parameters are evaluated by a neuronal network and include a statistical evaluation of the manually initiated shifts and an assessment of those shifts in relation to fuel consumption and the traction power of the drive engine. The learning mode is terminated when the changes of learned shift characteristics brought about by further manually initiated shifts remain within specified tolerance limits.
From DE 197 52 623 C2 a control system for an automatic motor vehicle transmission is known, in which the shifting behavior of the multistep change-speed transmission can be influenced by carrying out shifts manually, without a special learning mode having to be activated for this. The driver-specific adaptation of shift characteristics takes place by virtue of fuzzy-production rules and is based on the superposed interpolation between at least two existing limit shift characteristics in each case.
In a further method known from DE 199 16 808 A1 at least one predefined driving program, i.e. the corresponding shift characteristics or performance graphs of an automatic mode, are assumed as given. The existing driving program is then modified in a driver-specific manner by evaluating operating parameters detected in the manual mode during manually initiated shifts. The operating parameters are detected and the existing driving program is modified in a learning mode that can be activated. During the modification of the existing driving program, safety-relevant parts of the program remain unchanged.
A similar method is described in DE 101 34 997 A1. This known method starts from an electronic control unit with a program memory, in which is stored a control program for controlling a transmission and if necessary a clutch, i.e. a shifting program for the automatic mode, as a function of sensor-determined operating parameters. The program memory also contains a program by means of which the existing control program can be adapted to the operating behavior desired by the driver on the basis of driver inputs such as manually initiated shifts. The driver-specific control program can be stored on an external data carrier such as a memory card that can even be used as a vehicle key.
All the above-described control devices and methods have in common that the determination of the driver-specific shift programs, i.e. special shift characteristics or shift performance graphs corresponding to the driver's wishes in each case, is based on the known operating parameters of the respective motor vehicle or drivetrain and on the modification of at least one existing shift program, and consists in the modification of shift characteristics or performance graphs established during the development of the vehicle. Without knowledge of the essential operating properties of the drivetrain and the presence of at least one basis shift program that serves as an initial data set, a driver-specific shift program cannot be determined by the known methods.
The operating parameters that are relevant for the control of a multistep change-speed transmission of a motor vehicle, in particular its drivetrain, and the shift characteristics and performance graphs of at least one shift program that can also be used as the initial data set for further, driver-specific shift programs, are determined as part of the development of a new motor vehicle or the application of a multistep change-speed transmission in another motor vehicle, by highly qualified technical personnel such as the development, testing and application engineers of the vehicle or transmission manufacturer concerned, and are stored in a data memory of the transmission control unit. Owing to the multiplicity of the functions involved, during this it is necessary to store several thousand parameters and characteristics just for the basic functions of the multistep change-speed transmission, such as evaluating transmission and clutch sensors, actuating gear and clutch control elements and controlling the time sequencing of shift operations, as well as further thousands of parameters and characteristics for each driving strategy, many of which, in the context of a new application, have to be changed or adapted for the new application. Until now this has taken place during elaborate and time-consuming test runs by corresponding technical personnel, since such parameter and characteristic values are for example input or changed by means of a laptop connected to the transmission control unit and perhaps also to the engine control unit.
Since this procedure is relatively elaborate and time-consuming and must be carried out by appropriately trained technical personnel, the purpose of the present invention is to indicate a method for controlling an automated multistep change-speed transmission, by virtue of which the technical personnel can be substantially assisted while determining parameters and characteristics for setting up or modifying a shift program.